[mythtv-users] Digital Audio with myth

[Steve Adeff]

On Monday 28 November 2005 18:20, Robert Denier wrote:
> On Monday 28 November 2005 04:56 pm, Steve Hodge wrote:
> > On 11/29/05, Robert Denier <rdenier at finiteinfinity.org> wrote:
> > > On Monday 28 November 2005 02:08 pm, Nick wrote:
> > > > On 25/11/05, Phill Edwards <philledwards at gmail.com> wrote:
> > >
> > > [snip]
> > >
> > > > That's because the S/PDIF is outputting a digital stream which the
> > > > receiver decodes and is responsible for amplifying. I don't think
> > > > it's possible to dynamically adjust a digital audio stream before it
> > > > hits the amp.
> > >
> > > It is always possible to scale numbers and a digital stream is just a
> > > stream of numbers.
> >
> > But there isn't necessarily a direct mapping between the numbers in
> > the stream and the volume of the resulting audio. Think AC3 and DTS
> > passthrough.
>
> A quick glance shows that the PCM control _does_ control the audio level of
> a CMI9761 when using mplayer to play a realaudio stream, but it doesn't
> seem to work in Myth.  Perhaps there is the beginning of a solution there
> or maybe I just need to set something.
>
> Obviously, as was stated above, this may be useless if the stream has some
> complex encoding and is just being "passed through", but it seems as if it
> should be at least possible to control the volume level in myth if the
> audio being decoding is just 2 channel stereo PCM audio compressed as
> mpeg3.
>
> -Robert

it must be changing the relative volume levels (dynamic range) and not the 
absolute level.

-- 
Steve